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registerInterestedDriver

Allows an IOService object to register interest in the changing power state of a power-managed IOService object.

Declaration

IOPMPowerFlags registerInterestedDriver(
 IOService *theDriver );

Parameters

  • theDriver:

    The driver of interest adds this pointer to the list of interested drivers. It informs drivers on this list before and after the power change.

Return Value

Flags describing the capability of the device in its current power state. If the current power state is not yet defined, zero is returned (this is the case when the driver is not yet in the power domain hierarchy or hasn't fully registered with power management yet).

Overview

Call registerInterestedDriver on the IOService object you are interested in receiving power state messages from, and pass a pointer to the interested driver (this) as an argument. The interested driver is retained until the power interest is removed by calling deRegisterInterestedDriver. The interested driver should override powerStateWillChangeTo and powerStateDidChangeTo to receive these power change messages. Interested drivers must acknowledge power changes in powerStateWillChangeTo or powerStateDidChangeTo, either via return value or later calls to acknowledgePowerChange.

See Also

Miscellaneous